you'll see the slowing. >>> are you ready for this? boats on the water, blue angels in the sky. it's going to be a busy weekend in san francisco. a bold understatement. >> no kidding. thousands are expected to flock to the marina green for another round of the america's cup world series. practice actually gets under way later today. >> that is right. bob redell is the captain of this live shot and is in san francisco right now with more on what's going on. hey, bob. >> reporter: ahoy. good morning to you, jon and laura. yes, we were talking about the ac-45s. these are 45-foot-long catamarans out on the bay starting today for practice for the america's cup, a world series competition and qualifying starts tomorrow, runs through sunday. now, those are catamarans. back in the day, they used to rate on mono hulls and in 1851 it was a yacht called the america that won a race around england that kicked off the america's cup. right now we're on a replica of that ship. it's 138-feet long. the tallest mast 105 feet tall and its skipper, this gentleman right here, troy sears, has owned th